SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '451a7b0050c847b00af4a16624fa5cb2234670cb7d46afc5ac8525cd3e1a08cf' 
  AND token = 'znpQtp/Zgzch+PJl3Wfoa4RAj0ywGiq/GbDm51HfjYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}